A technique to improve the safety and utility of a vehicle in off-road traveling has been proposed. For example, as the technique, a crawl control (Crawl Control) technique is given. The crawl control is a technique to support a driving operation of a driver on a road surface such as a rockbound road, a snowy road, or a steep slope which requires a driver to execute fine speed control.
In the crawl control, the driver optimally controls the engine and the brake to cause the vehicle to travel at a low speed (for example, 1 to 5 km/h) set by the driver to make it possible to minimize slipping of the wheels.
In off-road driving, high driving force is required to cause the vehicle to run over a step formed of an obstacle or the like. However, a situation in which, after the vehicle runs over the step by outputting high driving force, the vehicle excessively accelerates to give a jumping-out feeling to the driver occurs. For this reason, there is a technique which, in order to improve braking response after the vehicle runs on the step, when it is determined that the vehicle runs on the step, actuates (gives preliminary braking force) a braking means not enough to substantially give braking force.